GMC 4000 Series Service Manual page 70

C a b Right ------- —
Sill Brackets.. Heater Line ^
\ Connec t i ons —
\ . A cce le rator Control.
\ v \ C on n ections
B ra ke Control H o se '
Clutch Control H ose
Righ t Support!
Torsion Bar
H ose C on n ectio ns
Torsion Bar
R igh t Fram e
Bracket
Stop Bracket
CHASSIS DISCONNECT POINTS
Figure 3 2 — Cab and Chassis Disconnect Points (Typical)
2. Raise cab and install support (if previously
removed) loosely to cab left s ill brackets.
NOTE: Cab tilt torsion bar, check link, and
right cab to sill support should be in position on
chassis as shown in lower view of figure 32.
3. Raise cab over chassis and lower into posi­
tion, forward slightly to clear shift control panel,
then back and down until steering gear coupling
can be engaged using marks made previously for
proper alignment.
4. Finish lowering cab until left support rests
on torsion bar. Install support cap with two bolts,
torque bolts to 50-60 foot-pounds.
5. Install check link retaining clevis pin with
cotter pin (A, fig. 30). Install bolt (C, fig. 30) into
rear hole of cab right s ill brackets and support.
6. Insert a pry bar in between cab right sup­
port and cab sill.
7. With two assistants, one holding pry bar
and the other helping to tilt cab forward (approx­
imately 45 degrees), install the three remaining
bolts, lock washers, and nuts (B, fig. 30) in the
right cab support and sill brackets. Use pry bar
to align bolt holes. Torque bolt nuts to 40-50 foot­
pounds.
8. Tighten steering coupling clamp bolt to 40-
50 foot-pounds torque. Connect speedometer cable
G M C S E R V I C E M A N U A L
' " T
Steering
Connection 1
C a b Left
Sill Bracket!
.eft Support]
A n d C a p
Stop Bracket
W ir in g Junction
Clutch Control
H ose C onnections
B ra ke Control
Steering
Connection
Torsion Bar
Left Fram e
Bracket
:
Lever
Figure 3 3 — Torsion Bar Tension Adjustment Lever Installed
and all electric connectors that junction with the
cab-to-chassis.
9. Connect accelerator linkage and adjust as
outlined under ENGINE FUEL SYSTEM (SEC. 6M).
Connect all ground straps.
10. Connect brake lines and hoses. Bleed the
brakes as outlined under "HYDRAULIC BRAKES"
(SEC. 5A) if equipped with hydraulic brakes.
11. Connect clutch flexible line and bleed as
outlined under "CLUTCH CONTROLS" (SEC. 7D).
12. Connect heater hoses and fill radiator.
13. Install bumper to front of frame. If vehicle
is equipped with air brakes, connect air lines.
14. Check cab tilting and lock action.
TILT CAB TORSION BAR
REPLACEMENT
A chain hoist and a lifting sling are required
to properly replace cab torsion bar as the weight
of cab must be removed from bar. Also, the aid of
one or more assistants is recommended.
REMOVAL
Instructions below pertain to cab replacement
procedures when cab is tilted (approximately 45
degrees) and suspended safely with weight of cab
removed from chassis. A chain from hoist hook,
down over rear center of cab and attached to cab
rear hold-down catch will a ssist in maintaining cab
safely at a 45-degree angle.
IMPORTANT: Protect top of cab from damage
by hoist equipment.
1. Secure hoist sling at rear of door openings.
2. Remove weight of cab from chassis.
3. Remove two retaining bolts from mounting
cap at torsion bar right frame bracket and from
support cap left support.
4. Remove bolt, nut, and washers which at­
tach torsion bar anchor lever to cab mounting left
Sec. 1
Page 63
TILT CAB